I use this interface to provide stereo digital IO between an iPad and another audio interface connected to my computer. As such, I cannot comment on the AD-DA capabilities.
Overall it works very well for the purposes I use it for. The sound is clear and the latency is negligible.
The ability to change the clock source and sample rate from the device would have been useful (as I am using it with an iPad and there is no iPad app for it, I cannot change these during use).
For those who are looking to rack mount it: it is quite easy to remove the rubber feet by unscrewing the front or back panel. Once this is done the unit fits exactly in 1U.
Overall recommended if you are looking for quick and easy stereo digital IO.